Tuesday, April 25, 2017

The ants of the genus Sericomyrmex -- literally translated as 'silky ants' -- belong to the fungus-farming ants, a group of ants that have figured out how to farm their own food. The silky ants are the less well-known relatives of the famous leaf-cutter ants.

At only four million years, Sericomyrmex is an evolutionary youngster, the most recently evolved genus of fungus-farming ants, and an example of adaptive radiation which is a process in which organisms diversify quickly into a multitude of forms, making these ants good candidates for studies into speciation and evolution.

The new species has been named after the famous British band Radiohead in honor of the musicians' environmental efforts, especially in raising climate-change awareness. This is one of my favorite bands which makes this even more exciting to me.

For the experts: The genus Sericomyrmex Mayr (Formicidae: Myrmicinae: Attini) is a Neotropical group of fungus-farming ants known for its problematic taxonomy, caused by low morphological variability across the species, vague and old species descriptions, and an outdated and incomplete key published in 1916. Recent molecular studies revealed that Sericomyrmex is the product of a rapid recent radiation, with a divergence date of 4.3 million years ago. Here we present a comprehensive taxonomic revision of the genus Sericomyrmex based on morphology and a recently published molecular phylogeny. We discuss and illustrate morphological characters for Sericomyrmex workers, males, queens, and larvae. We report 18 standard morphological measurements and 5 indices for 529 workers, 50 queens, and 39 males, which we employ in morphometric analyses. The revised genus Sericomyrmex comprises eleven species, including three new species, here described as S. maravalhas sp. n., S. radioheadi sp. n., and S. saramama sp. n. We also redescribe S. amabilis Wheeler, S. bondari Borgmeier, S. lutzi Wheeler, S. mayri Forel, S. opacus Mayr, S. parvulus Forel, S. saussurei Emery, and S. scrobifer Forel. The number of recognized species (11) is lower than the previously recognized 19 species and 3 subspecies. The following species and subspecies are synonymized: under S. opacus [=S. aztecus Forel syn. n., S. zacapanus Wheeler syn. n., and S. diego Forel syn. n.]; under S. bondari [=S. beniensis Weber syn. n.]; under S. mayri [=S. luederwaldti Santschi syn. n., S. moreirai Santschi syn. n., S. harekulli Weber syn. n., S. harekulli arawakensis Weber syn. n., S. urichi Forel syn. n.]; under S. saussurei [=S. burchelli Forel syn. n., S. impexus Wheeler syn. n., S. urichi maracas Weber syn. n.]; and under S. parvulus [=S. myersi Weber syn. n.]. We provide a key to Sericomyrmex species for the worker caste and information on the geographic distributions of all species.

Thursday, April 13, 2017

Pistol shrimps, or snapping shrimps, have an ability to generate substantial amounts of sonic energy. By closing its enlarged claw at rapid speed the shrimp creates a high-pressure cavitation bubble, the implosion of which results in one of the loudest sounds in the ocean - strong enough to stun or even kill a small fish.

A newly discovered conspicuously coloured pistol shrimp found on the Pacific coast of Panama has now been named Synalpheus pinkfloydi in recognition of the discoverers' favourite rock band -- Pink Floyd.

As a lifetime fan of the band I can only applaud my colleague for this decision.

For the experts: A new, conspicuously coloured species of the alpheid genus Synalpheus Spence Bate, 1888, is described based on material collected on the Pacific coast of Panama. Synalpheus pinkfloydi sp. nov. is closely related to the western Atlantic S. antillensis Coutière, 1909, the two taxa being transisthmian, cryptic sister species. Both species are characterised by the distal areas of their major and minor chelae coloured in an intense, almost glowing pink-red. The morphological differences between S. pinkfloydi sp. nov. and S. antillensis Coutière, 1909 are subtle, being limited to the slightly different proportions of the merus of both chelipeds, distodorsal armature of the major cheliped merus, relative length of the antennal scaphocerite, and body size. However, they are genetically different with a 10.2% sequence divergence in COI. Based on molecular clock estimates, these transisthmian taxa diverged around 6.8–7.8 mya, i.e. well before the final closure of the Isthmus of Panama 2.5–3 mya.